No abstract

The long-wavelength fluorogenic derivatization method for aryl halides was developed based on the stilbene formation by the Heck coupling reaction between aryl halides and vinylbenzenes in the presence of palladium (II) acetate as a catalyst.Fluorescent maximum wavelengths of the derivative obtained by the proposed reaction were 365-450 nm, which were 50-100 nm longer than those of the biphenyl derivatives formed with the our previously developed fluorogenic derivatization method. Also, by the investigation using vinylbenzenes that containing electron-donating or -withdrawing functional groups, an internal charge transfer system could contribute to extend emission wavelength of the derivative. Furthermore, the proposed reaction was applied to develop a pre-column derivatization HPLC with fluorescence detection method for aryl bromides using 4-vinylanisole. p-Substituted aryl bromides (i.e., p-bromobenzonitrile, p-bromoanisole, bromobenzene, p-bromobenzoic acid ethyl ester, p-bromotoluene) derivatives were successfully detected within 40 min with the detection limit of 0.007-0.264 µM. Despite the short reaction time of 10 min, the reaction yields for pbromoanisole and bromobenzene were good at 101% and 87%, respectively.